Automatic material holdback means for sewing machines



May 20, 1941. M. UNGER UTOMATIC MAT-ERIAL HOLDBACK MEANS FOR SEWINGMACHINES Filed July 23, 1940 3 Sheets-Sheet 1 Meyer Unger May 20, 1941.M. UNGER AUTOMATIC MATERIAL HOLDBACK MEANS FOR SEWING MACHINES FiledJuly 25, 1940 s shects-sheet 2 v Meyer nge# May zo, 1941. M, UNSER2,242,689

AUTOMATIC MATERIAL HOLDBACK MEANS FOR SEWING MACHINES Filed Ju1y 23,1940 s sheets-.sheet 5 D@ Wijf?? '16@ 75 l A (@3111) 13W u u m M676? 1/er Patented May 20, 1941 AUTMATIC MATERIAL HOLDBACK MEANS FOR SEWENGMACHINES 12 Claims.

This invention relates to automatic material hold-back means for sewingmachines and is. of the general type disclosed in the application forpatent filed by Meyer Unger on March 15, 1940, Serial Nol 324,181, andprovides as an improvement thereover a simplied construction foraccomplishing the objects ascribed to the invention disclosed in saidapplication.

A further object of the present invention is to provide an attachmentfor a sewing machine of any type, the hold-back foot being operative forarresting movement of the material after the same passes the usualpresser foot and including a worm on the shaft beneath the bed plate ofthe sewing machine that has the shuttle associated therewith, with theworm driving a worm wheel that in turn operates devices associated withthe hold-back foot for rendering said devices operative at predeterminedintervals when a predetermined number of stitches have been taken toeffect raising of the hold-back foot so that the sewed material will befree of all stretching action normally inherently produced by thetendency of the operator to pull the material by hand rearwardly of apresser foot.

The invention further includes manually operable means for raising thehold-back foot at will and a knee-operated or other lever to eiectsimultaneous raising of the pressure foot and hold-back foot for therelease of material when desired.

With the above and other objects of the invention that will becomeapparent as the nature thereof is better understood, the same consistsin general of certain novel details of construction and combination ofparts hereinafter more fully described, illustrated in the accompanyingdrawings and claimed.

In the drawings:

Figure 1 is a side elevational view, partly broken away, of a sewingmachine equipped with an automatically operating material hold-back footand the devices associated therewith,

Figure 2 is an outer end elevational view of the head of the sewingmachine, showing the tensioned hold-back foot disposed rearwardly of thepresser foot,

Figure 3 is a fragmentary side elevational view, partly in section, ofthe head end of the sewing machine with the hand-operated lever forraising the hold-back foot illustrated in dotted lines together with thehold-back foot in raised positions,

Figure 4 is a horizontal sectional view taken on line 4 4 of Figure 3,

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Figure 5 is a fragmentary bottom plan View showing a worm on the shuttleshaft engaged with the worm wheel that operates the devices forperiodically raising the hold-back foot,

Figure 6 is a fragmentary end elevational view showing the driving beltguide,

Figure 7 is a detail sectional view taken on line '1 -'I of Figure 5,showing a lug facially projecting from the worm wheel for engagementwith a cam on an operating arm of the mechanism for raising thehold-back foot, and

Figure 8 is a detail sectional view taken on line 8 8 of Figure 5.

The hold-back foot attachment is associated with a sewing machine ofstandard construction that includes a bed plate I5 that has a hollowupright IS rising from one end thereof, the upper end of the uprightcarrying a lateral horizontally extending overhanging hollow arm I 'lthat carries at its free end above the bed plate I5 a vertical hollowhead I8. A horizontal drive shaft I9 extends through the upper end ofthe upright I6 and the overhanging arm Il, the end of the horizontalshaft i9 projecting outwardly of the upper end of the hollow upright IE5carrying a fly wheel ZIJ and a belt drive sheave ZI The other end of theshaft I9 has a conventional driving connection with the bar 22vertically reciprocable in kthe hollow head I8, the bar 22 carrying atits end the usual sewing machine needle 23. A downwardly tensionedvertically sliding bar 24 is mounted in the head I8 and carries at itslower end an ordinary presser foot 25 that engages the throat plate 26of the bed plate I5, the downwardly tensioned bar 2d carrying the usualabutment to be engaged by the cam lever 2l to effect manual raising ofthe presser foot 25.

The automatically operating material holdback foot attachment for thesewing machine includes a mounting plate 28 overlying a side of thehollow head I8 with an angle arm 29 carried thereby with an openingtherein for lthe passage of the threaded bolt 3Q upon which the camlever 2l for raising the presser foot is pivoted, the

nut 3l threaded upon the bolt 3 retaining the mounting plate in positionwhile the two screws 32 threaded through the mounting plate 28 areengaged with the hollow head I8 to effect a substantial support for themounting plate. The plate 28 is provided with a slotted opening 33 forthe passage of the cam lever 21. A tubular guide 34 is carried by oneedge of the mounting plate 28 in the vertical plane with and rearwardlyof the downwardly tensioned rod 24 as illustrated.

A rod 35 is vertically slidable in the tubular guide 34 and is of alength to project at all times above and below said guide, the lowerprojecting end of the rod 35 in proximity of the lower end of thetubular guide being threaded' as at 35 for a portion of its length forthe reception of an adjustable nut 37 while a coil spring 38 surroundsthe rod 35 between said nut 37 and the lower end of the tubular guidefor normally tensioning the rod 35 in a downward direction. A holdbacl:foot 39 is adjustably mounted upon the lower end of the rod 35 and ispositioned postjacent the presser foot 25 as shown in Figure 2.

The operating means for the rod 35 carrying the hold-back foot 39includes a lever pivoted intermediate its ends on the horizontal pinlill projecting laterally of the overhanging arm Il, the opposite leverarms 4I and 42 of the lever extending longitudinally of the overhangingarm l'l with the end 42 having a pivotal connection 43 with the upperend cf the rod 35. The free end. of. the lever arm ill is adjustablyattached to the upper end of a vertical. rod it by means of the` nut 45threaded on. the upper endi of said rod lill and. engaged withthe upperside of the lever arm di, the lower end of said. rody lil as shown inFigures 1 and 5 extending downwardly through an opening 43 in the bedplate l5 with a hook 1l upon its lower terminal end engaged in anopeningin the nattened end 43 ofV a lever 49 thatA is pivotally mounted beneaththe bed plate I5.- at. the other end thereof asshown at 55. upon a` pinl depending from the bed plate. It will be understood that the rod 35 isdownwardly tensioned by the spring. 33' which normally Inovesthe freeend of the lever arm 42 in a downwarddirection and the free end. of thelever arm 4I in an upward direction sothatthe free end of the lever 45is normally at. its limit of'V upward movement. on its pivot bearing55'.

The material hold-back foot 39'may be raised at will by means ofmanually operated devices shown more clearly in Figures l and 3 ascomprisingY a. disk cam 52 eccentrically mounted as at; 53Y upon theupper end of the mounting plate 2S; and carrying` a manipulating handle5d, the cam" and handle being shown in their shifted dotted linepositions. in Figure 3 with the cam 52engaged with the underside of thefree end of the lever arm 43' for raising the same and carryingtherewith against the tension oi the spring 38,' the rod. 35 andmaterial hold-back foot. 39 at the lower end of said rod. The handle 54.is.v limited in its. downward movement to an inoperative position bymoving into. engagement with the upper screw 32 that aids in securingthe mounting plate 28 in position.

It is intended that the. sewing machine needle 23; produce apredetermined number of stitches while the material hold-back foot 39yis in its lower operative position andto accomplish this object. devicesare provided to effect periodic pivotal' movements of the lever ttl-onits pivot bearing 53', these devices including the longitudinallyextending drive shaft4 55 below the bod plate l5. that. hasA a beltconnection 55 extending upwardly through the hollow upright l5 to apulley 5T. upon the drive shaft I9, the belt being twisted as shown inFigure 1 and carrying parallel; rows of spaced outwardly projecting pins58 while a guide frame 59.carried by the lower side y" ofjthe bed platel5 as shown in Figures 5 and 6 has enarcuate edge 5t slightly spacedfrom said Ibelt between said rows of. pins to assure proper tracking ofthe belt 5.5. on the shaft 55. The shaft 55 at its opposite end has thesewing machine shuttle associated therewith. A worin 5l is xed to theshaft intermediate the ends thereof.

A worm wheel G2 is journaled upon a pin 53 depending from the lower faceof the bed plate l5 and is engaged with the worm Si, the worm wheel 62at a point between the pivot 63 and peripheral edge thereof overlyingthe lever 49 in proximity of the lower pivot pin 5 l. An abutment lugdepends from the worm wheel 52 inwardly of the peripheral edge thereofand is adapted during rotation of the worm wheel to move into engagementwith a cam t5 rising from the lever B9 for moving the lever on its pivotbearing 5| and exerting a downward pull on the rod 44 to operate thelever arms di and l2 to raise the rod 35 carrying the material hold-backfoot 39. When the abutment lug 64 is carried beyond the cam E55, thedownwardly tensioned rod 35 raises the free end of the lever 139 andeffects lowering movement of the material holdbackrfcctSS into itsmaterial hold-back position.

Should it be desired to simultaneously raise the presser foot 25 and thematerial hold-back foot 39 by a single operation, there are provideddevices including a lever having lever arms 55 and El' pivo-tedVintermediate their ends upon the lever pivot @El as shown in Figure l.The free end of the'lever arm El as shown in Figure 2 carriesaj pinextension 53 that projects into a laterally offset .portion of thehollow head I8 that works ina slot 69' in an arm 'lil carried by andmovablewith the sliding bar 24. that carries the presser foot 25, thepin extension 68 being normally positioned at the upper end of the slot59 so as not to interfere with the normal operation ofthe sliding barv2G by the cam lever 2l. The free end of the lever arm 55 is pivot-allyattached as at il to a head 'l2 that carries a depending rod 'E3 that isattached at its lower end as at M to one end of a knee-operated leverl5l that is pivoted intermediate its ends as at 'E6 upon a bracket rarm71 depending from the bed plate I5, the connection 'M between the lowerend of the rod` 73 and the knee-operated lever 'l5 being superjacent theend i3 of thelever 49 so that when the lever 'l5 is operated the pinextension upon the lever arm El raises the sliding bar 25y carrying thepresser foot 25v by its engagement in a slot in the arm 'F0 while theend of the lever 75 to which the rod '13I is attachedpresses downwardlyupon the end i8 of the lever t9. for raising the lever arm 42 and rod.35' carrying the material hold-back foot 39.

From theY above detailed description of the invention it is believedthat the construction and operation thereof will at once be apparent, itbeing noted that the material fed rearwardly under thepresser foot 25 isheld back by the downwardly tensioned material hold-back foot 39-untilthe holdf-back. foot is raised by rotation of the worm wheel 62 thatcarries the abutment lug 54 into engagement with the cam onl the lever63, the stitched material being-then automatically extended beyond thehold-back foot with the latter promptly lowering to its materialhold-back position when the abutment lug te is` moved beyond the cam S5during continuous rotation of the worm wheel 62. Those materialsordinarily subjected to stretching activities by an operator who usesher hand for the drawing of the material rearwardly of the presser footare not subjected to any stretching activities and-it is possible to sewmaterials on the bias and materials of any weightwithout any stretchingaction the materials.

While there is herein shown and described the preferred embodiment ofthe invention, it is to be understood that minor changes may be made inthe details of construction, such as will fall within the scope of theinvention as claimed, it being further noted that the material hold-backfoot is spaced rearwardly of the usual material feed dog associated withthe presser foot and engages a smooth part of the throat plate of thesewing machine.

I claim: e

1. Automatic material hold-back means for sewing machines, wherein thesewing machine includes a bed plate, a presser foot, a material feedingdog, operating means for the dog and a rotatable shaft beneath the bedplate, an automatically operated material hold-back foot postjacent thepresser foot and normally positioned to hold back material passedrearwardly of the presser foot, a downwardly tensioned rod carrying thehold-back foot and gear drive connections between the shaft and rodoperative at intervals to raise the rod and material hold-back foot torelease the held-back material.

2. Automatic material hold-back means for sewing machines as set forthin claim 1, wherein independently operating means are provided forseparately raising the presser foot and the material hold-back foot.

3. Automatic material hold-back means for sewing machines as set forthin claim 1, wherein independently operating means are provided forseparately raising the presser foot and the material hold-back foot andmanually operated means for simultaneously raising the presser foot andmaterial hold-back foot.

4. Automatic material hold-back means for sewing machines, wherein thesewing machine includes a bed plate, a presser foot, a material feedingdog, operating means for the dog and a rotatable shaft beneath the bedplate, an automatically operated material hold-back foot postjacent thepresser Afoot and normally positioned to hold back material passedrearwardly of the presser foot, a downwardly tensioned rod carrying thehold-back foot and gear drive connections between the shaft and rodoperative at intervals to raise the rod and material hold-back foot torelease the held-back material, the gear drive connections including aworm on said shaft, a worm wheel driven by said worm, a series of leversand links with an end lever of the series operatively engaged with therod carrying the hold-back foot and with the other end lever of theseries being adjacent said worm wheel and cooperating means carried bysaid worm wheel and said last named lever f said series adaptedperiodically to operate the links and levers for raising the rod andmaterial hold-back foot,

5. Automatic material hold-back means for sewing machines as set forthin claim 1, wherein independently operating means are provided forseparately raising the presser foot and the material hold-back foot, thegear drive connections including a worm on said shaft, a worm wheeldriven by said worm, a series of levers and links with an end lever ofthe series operatively engaged with the rod carrying the hold-back footand with the other end lever of the series being adjacent said wormwheel and cooperating means carried by said worm wheel and said lastnamed lever of said series adapted periodically to operate the links andlevers for raising the rod and material hold-back foot.

6. Automatic material hold-back Vmeans for sewing machines as set forthin claim l, wherein independently operating means are provided forseparately raising the presser foo-t and the material hold-back foot andmanually operated means for simultaneously raising the presser foot andmaterial hold-back foot, the gear drive connections including a worm onsaid shaft, a worm wheel driven by said worm, a series of levers andlinks with an end lever of the series operatively engaged with the rodcarrying the hold-back foot and with the other end lever of the seriesbeing adjacent said worm wheel and cooperating means carried by saidworm wheel and said last named lever of said series adapted periodicallyto operate the links and levers for raising the rod and materialhold-back foot.

7. Automatic material hold-back means for sewing machines `as set forthin claim 1, wherein independently operating means are provided forseparately raising the presser foot and the maeri-alV hold-back foot,the presser foot raising means including a vertically slidable barcarrying the presser foot, and a ca-m lever engageable With said bar forraising the same, and the material hold-back foot raising meansinclu-ding a lever pivoted on the sewing machine with one end thereofconnected to the upper end ofthe downwardly tensioned rod 'and a handoperated cam lever pivoted on the machine adapted to move the lever onits 'pivot to raise the material hold-back foot.

8. Automatic material hold-back means for sewing machines as set forthin claim 1, wherein independently operating means are provided forseparately raising the presser foot and the material hold-back foot, thepresser foot raising means including a vertically slidable bar carryingthe presser foot, and a cam lever engageable with said bar for raisingthe same, and the material hold-back foot raising means including alever pivoted on the sewing machine with one end thereof connected tothe upper end of the downwardly tensioned rod land a han-d operated camlever pivoted on the machine adapted to move the lever `on its pivot toraise the material holdback foot, and manually operated means forsimultaneously raising the presser foot and material hold-back foot,including a lever pivoted on the machine, ya pin and slot connectionbetween one end of the lever and the support for the presser foot, alink rod depending from the other end of the lever extending downwardlythrough the bed plate of the machine, a kneeoperated lever pivoted onthe bottom of the bed plate and to one end of which the depending linkrod is attached, a second depending link rod carried by the other end ofthe lever attached to the rod carrying the material hold-back foot, aworm wheel-operated lever beneath the bed plate for operation of saidsecond-named link rod and said worm wheel-operated lever being arrangedin the operative path of movement of the knee-operated lever foroperation by the latter.

9. Automatic material hold-back means for sewing machines `as set forthin claim 1, wherein the gear drive connections include a worm on saidshaft, a worm wheel driven by said worm, a series of links and leverswith the worm wheel overlying a lever of said series, an abutment lugfacially depending from said worm wheel and an abutment cam on the leverunderlying said worm Wheeladapted to be engaged by said abutment lugduring rotation of the Worm wheelA for operating the series of links andlevers for the raising of the material hold-back foot.

10. Automatic material hold-back means for sewing machines as set forthin claim 1, wherein the gear drive connections include a worm on saidshaft, a Worm wheel driven by said worm, a series of links and leverswith the wormwheel overlying a lever of said series, an abutment lugracially depending from said worm wheel and an abutment cam on the leverunderlying said Worm Wheel adapted to be engaged by said abutment lugduring rotation of the worm Wheel for operating the series of links andlevers for the raising of the material hold-back foot, a looseconnection in said series of links and levers and a manually-operatedcam adapted to shift a lever of said series connected with said rod forraising the material hold-back foot at will.

11. Automatic material hold-back means for sewing machines as set forthin claim l, wherein the gear drive connections include a worm onsaidshaft, a ,worm wheel driven by said Worm, a series of links andlevers with the Worm Wheel overlying a lever of said series, an abutmentlug facially depending from said worm wheel and an abutment cam on thelever underlyingY said worm wheel adapted to be engaged by said.abutment lugduring rotation of the worm wheel for operating the seriesof links and levers for the raising of the material hold-back foot andmanually-operated means for'simultaneously raising the presser foot andmaterial hold-back foot including a knee-operated lever operativelyengaged With the presser foot and adapted for operation of theWorm'wheel-operated lever.

12. Automatic material hold-back means for sewing machines as set forthin claim 1, wherein the gear drive -connections include a wor-rn on saidshaft, a Worm Wheel driven by saidvvorm, a series of links and leversWith the Worm. wheel overlying a lever of said series, an abutment lugracially depending from said Worm. wheel and an abutment cam on thelever underlying said worm wheel adapted to be engaged by said abutmentlug `during rotation of the Worm Wheel for operating the series of links`and levers for the raising of the material hold-backfoot, a looseconnection in said series of links and levers and a manually-operatedcam yadapted to shiftva lever of said series connected with said rod forraising the material hold-back foot at will, and manually-operated meansfor simultaneously raising the presser foot and material holdback footincluding a knee-operated lever operatively engaged with the presserfoot 4and adapted for operation of the worm wheel-operated lever.

MEYER -UNGER.

